Albert Barnes Commentary 1 Kings 20:31

"And his servants said unto him, Behold now, we have heard that the kings of the house of Israel are merciful kings: let us, we pray thee, put sackcloth on our loins, and ropes upon our heads, and go out to the king of Israel: peradventure he will save thy life." — 1 Kings 20:31 (ASV)

And ropes upon our heads — “Ropes about our necks” is probably meant. They, as it were, put their lives at Ahab’s disposal, who, if he chose, could hang them at once.